Work to clean and repair interior sections of the Wawona Tunnel at Yosemite National Park will lead to occasional traffic delays beginning Sunday and extending into December.

The historic tunnel, completed in 1933, leads to "Tunnel View," one of the most iconic and beautiful vistas in the National Park System. Millions of visitors flock to "Tunnel View" each year to witness and photograph spectacular vistas of Yosemite Valley.

Most of the construction will occur inside the tunnel and incremental traffic delays will be instituted during the construction period, which begins September 8 and is scheduled to run through December 13, a park release said.

The work is needed to clean and repair the Wawona Tunnel. It will include repairing sections of the tunnel wall, floor, and ceiling, sealing cracks and joints, improving the drainage system, and cleaning the interior of the length of the tunnel, the park said.

Traffic delays will be scheduled throughout the duration of the construction project. However, no delays will occur over weekends or holidays. Throughout the project, there will be controlled traffic and pilot car operations. The public is urged to drive with caution during the duration of the construction.

The schedule for the traffic delays is as follows:

Sunday, September 8 through Sunday, September 29

Sunday evening at 8 p.m. to Friday afternoon at 4:30 p.m., traffic delays will occur from 8 p.m. to 6 a.m. (delays up to 30 minutes)

6 a.m. to 8 p.m. (delays up to 15 minutes)

Monday, September 30 through Thursday, December 13

Sunday evening at 8 p.m. to Friday afternoon at 4:30 p.m., traffic delays will occur from 8 p.m. to 10 p.m. (delays up to 30 minutes)

10 p.m. to 6 a.m. (delays up to two hours)

6 a.m. to 8 p.m. (delays up to 15 minutes)